TITLE: GCN CIRCULAR NUMBER: 14855 SUBJECT: GRB 130606B: Swift/UVOT Upper Limit DATE: 13/06/10 15:38:48 GMT FROM: Craig Swenson at PSU/Swift C. A. Swenson (PSU) and D. Kocevski (NASA/GSFC/ORAU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 130606B 106.6 ks after the Fermi/LAT trigger (Vianello et al., GCN 14795). No optical afterglow consistent with the position of the potential X-ray candidate (Kennea, GCN 14820) is detected in the UVOT exposures. A preliminary 3- sigma upper limit using the UVOT photometric system (Breveld et al., 2011, AIP Conf. Proc. 1358, 373) for the initial exposures is: Filter T_start(s) T_stop(s) Exp(s) Mag ------ ---------- --------- ------ --- White 106556 123017 4142 >22.6 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.10 in the direction of the burst (Schlegel et al. 1998)